Publications

The authors cultured 2,320 patients who attended the Denver Metro Health Clinic for Sexually Transmitted Diseases from September 1981 to June 1983 to determine clinical and epidemiologic factors associated with genital chlamydial infection. Among consecutive heterosexual men with urethral discharge, 226 of 849 (27%) had positive urethral cultures, with rates significantly lower among those with profuse (18%) or purulent (19%) discharges, and higher (37%) among those with symptoms for more than seven days. In a subgroup of men without gonococci, those who had polymorphonuclear leukocytes on smear had higher isolation rates (33%) than those who did not (3%). Among consecutive female patients, 172 of 1,031 (17%) had positive cervical cultures, with rates significantly lower in those who were white (13%), married (7%), or using a diaphragm (0 of 77), and higher in those who were positive for Neisseria gonorrhoeae (38%). There was a marginally significant increased rate of chlamydial isolation among oral contraceptive users only for women aged 20 years or younger. Younger age was significantly associated with chlamydial isolation in both men and women after controlling for sexual activity and other factors. Various patient characteristics can be combined to define subgroups of men and women, with rates of isolation ranging from under 4% to over 60%. These results can be useful in deciding whom to test and whom to treat presumptively in a public health setting.

Experiments were performed to determine the effect of hematoporphyrin derivative (HPD) photodynamic therapy on blood flow to normal rat intestine. A segment of rat jejunum was exposed to red (greater than 590 nm) light (200 mW/cm2) 24 h after the i.v. administration of HPD. Blood flow to the light exposed segment was determined using the radioactive microsphere technique while blood flow to an adjacent light shielded segment of intestine served as an internal control. Animals were divided into six groups of six each: Group I, no HPD, no light; Group II, light, no HPD; Group III, HPD (20 micrograms/g body weight), no light; and Group IV, HPD (20 micrograms/g body weight), light. Blood flow in these four groups was determined 10 min after completion of a 30-min exposure to light. Only in Group IV was there a statistically significant decrease (P less than 0.005) in blood flow to the segment treated with HPD and light. In Groups V [HPD (20 micrograms/g body weight), light] and VI [HPD (10 micrograms/g body weight), light] blood flows were determined 24 h after exposure to light. In both of these groups there was also a significant (P less than 0.05) decrease in blood flow in the segment treated with HPD and light. This study demonstrates that normal intestinal blood flow can be disrupted by HPD photodynamic therapy.

The heads of 2-day-old male and female rats were irradiated with a single dose of 600 rads X irradiation, a dose which is known to stunt body weight, tibial length, and tail length, in order to ascertain its effects on synthesis by cartilage of sulfated proteoglycans, DNA, chondroprotein, and collagen as determined by utilization of [35S]sulfate, [Me-3H]thymidine, [1-14C]leucine, and [3,4-3H]proline, respectively. Data have been collected at 20-21, 23, 41-45, and 70-71 days of age. In comparison to controls, growth in body weight, tibial length, and tail length was significantly retarded in irradiated rats of both sexes. Although slow catch-up growth was observed with respect to tail length in both sexes and tibial length in females, a significant deficit in body weight in irradiated rats in both sexes remained at 70-71 days. Cartilage metabolism as evidenced by incorporation of the labeled substances showed no significant disturbance just prior to weaning (20-21 days) or after completion of the principal growth surge (70-71 days). Reduced sulfate and thymidine incorporation attributable to a brief period of undernutrition associated with weaning occurred in head-irradiated rats immediately following weaning (23 days). Increased isotope incorporation occurred at 41-45 days of age in cartilage of irradiated rats incubated with labeled sulfate, leucine, and proline; it did not increase with labeled thymidine. We conclude that neonatal head irradiation slows the rate of growth through the age of most rapid postnatal growth in normal rats. The pattern of cartilage metabolism during this time can be the result either of stimulation by a factor other than somatomedin, or selective inhibition of cartilage thymidine incorporation acting in combination with somatomedin.

The heads of 2 day old male and female rats were X-irradiated with 600 rad. Non-irradiated littermates served as controls. At 40 days of age groups of irradiated and non-irradiated rats were subjected to a 48 hour fast. Non-fasted groups of irradiated and non-irradiated rats were fed ad lib. and were used for comparative studies. Growth of body weight and tail length was recorded at intervals through 70 days of age. At sacrifice, pituitary weight, tibial length, and tibial epiphyseal width were also determined. The results confirm earlier findings that whole head irradiation produces reduced growth of body weight and of tail length which remains uncompensated by catch-up growth. After fasting and then refeeding normal catch-up growth acceleration occurred in both male and female irradiated and nonirradiated animals. The fasted non-irradiated animals caught up to the non-irradiated control rat size for both body weight and tail length. Similarly, the fasted irradiated rats caught up to the irradiated, non-fasted rat size, but did not catch up to the size of the non-irradiated controls. Pituitary weight and tibial length were significantly reduced in irradiated males and females. At sacrifice, no significant difference existed between the fasted and non-fasted subgroups. The tibial epiphyseal growth plate was not narrowed in irradiated rats; fasted rats had increased epiphyseal width during recovery in only one group. We conclude that the catch-up growth control is intact in the head-irradiated stunted rat. The findings suggest that the mechanism which recognizes normal body size (set-point for body size) and which determines the limit of catch-up growth acceleration is reset for a smaller body size by the head-irradiation.

UNLABELLED: In order to determine the effect of subfracture loads on articular cartilage, we impacted twelve adult canine patellofemoral joints utilizing a drop-tower with two different force-levels. The joints were examined with light and electron microscopy at two, four, and six weeks after impaction. In ten additional animals a single knee was impacted and they were analyzed biochemically at similar time-periods, using the contralateral joint as a control. In all impacted specimens changes were observed in the zone of calcified cartilage, represented by an increase in cellular clones, vascular invasion, and proteoglycan content of the matrix. Ultrastructural evaluation of the superficial and deep radial zones of the articular cartilage revealed loss of the cellular processes and territorial matrices of chondrocytes in both layers. Ruthenium-red staining of impacted samples revealed a 40 per cent decrease in proteoglycan associated with collagen fibers in the extraterritorial matrix. An increase in collagen-fiber width was observed in the four and six-week groups. The earliest changes in articular cartilage included activation of the zone of calcified cartilage as well as ultrastructural alterations in the superficial and radial zones. Biochemical analysis revealed an increase in water content and hexuronic acid at two weeks. These changes occurred at a subfracture level in the absence of surface disruption.

CLINICAL RELEVANCE: These animal experiments indicate that adult articular cartilage may show significant alterations in its histological, biochemical, and ultrastructural characteristics without disruption of the articular surface. This model of articular cartilage "contusion" may represent a corollary to the joint damage that is observed following direct blunt trauma transmitted across articular surfaces without radiographic evidence of fracture. The possibility that this form of injury may be the precursor of chondromalacic changes in patellar or femoral cartilage merits further study.

Participation of non-choroidal elements, particularly of ventricular ependyma, in CSF production is well recognized. The present investigation is an attempt to elucidate possible surface changes in the ventricular lining following chronic acetazolamide administration in the rat. A progressive time-dependent change was observed in the ependyma of the third ventricle. In the dorsal ciliated zone the appearance of dilatations and surface evaginations on cilial shafts were the predominent features. The ventral non-cilated area was characterized by eruption of blebs and microvilli with apical swellings. The significance of these surface fine structural changes are discussed in the light of available studies. It appears that the ependyma is stimulated into increased activity. However, the precise nature of such a response–whether secretory or absorptive–must remain conjectural until correlative scanning and transmission electron microscopic data become available.

Surface changes in the epithelium of the choroid plexuses of the lateral and third ventricles of rats induced by chronic administration of acetazolamide have been studied by scanning electron microscopy. After 3 weeks atrophic changes were evident, the microvilli and blebs normally seen on the ventricular surface of the cells appeared attenuated, and in extreme cases they disappeared, leaving the cell surface completely denuded. Localized areas of hypertrophy, indicated by secondary spherical budding, were occasionally observed. The atrophic changes accord with the known inhibitory effects of acetazolamide on CSF formation: perhaps the small number of cells undergoing hypertrophy compensate to some extent for the atrophic ones and maintain some CSF secretion.